Neonatal cardiac surgery: assessment and comparison of surgical results using the RACHS-1 risk adjustment method

The RACHS-1 method (Risk Adjustment for Congenital Heart Surgery) is widely used to predict mortality and risk adjustment in pediatric cardiovascular surgery and constitutes a valid tool to compare results among different health centers. To analyze if the mortality observed in the neonatal group is related to age and/or the risk stratification according to RACHS-1. From March 2001 to May 2008 we operated on 751 consecutive patients: 160 neonates (0-30 days), 309 infants (31 days-1 year) and 282 olders (1-18 years). Patients in each group were analyzed according to age, RACHS-1, and mortality. We used a logistic regression in which the mortality was the dependent variable and the age and RACHS-1 the independent variables. The total crude mortality was 4.3%, the neonatal 9.2%. We observed a significant statistical difference of RACHS-1 distribution according to age (chi(2)= 219, p< 0.0001). Logistic analysis showed no statistical difference of mortality (p> 0.05) in the age groups compared to RACHS-1. Furthermore, RACHS-1 is a most powerful mortality predictor (p< 0.001) while age is not (p= 0.8). Using our unit one of RACHS-1 as control group, the odds ratio of the different ages were 2.1 (CI 95%: 1.6-2.7) for each RACHS group. The age of surgery was not an independent risk factor as to mortality. The RACHS-1 method appeared as a powerful risk factor predictor of mortality; no differences were found in the age groups when classified by RACHS -1.